Dental devices in general and dental implants in particular are made basically of two classes of materials: metals and ceramics.
With regard to metal, several metals are used for forming implants. Each metal has its own characteristic which renders the metal a possible suitable choice for the dental implants. For example, Ti (titanium) or titanium alloy are generally used. Titanium dental implants are relatively light, have high strength, and they have excellent corrosion resistance and bio-compatibility.
Ceramic materials such as zirconia-based, alumina-based and/or sapphire-based ceramics have also been used for manufacturing dental implants or dental devices.
Dental devices, in general, and dental implants, in particular, formed from ceramic materials have the disadvantage that the material is more brittle as shown by a low value for the notched bar impact test. Ceramic materials are also susceptible to uncontrolled internal and external micro-cracks, and therefore they are prone to fail catastrophically. Moreover, artificial ceramic dental devices are rather expensive. However, the ceramic dental devices in general and the visible section of dental implants in particular, have a better aesthetic impact with respect to the metal implant and therefore enjoy a higher acceptance with the dental device bearer.
Furthermore, in some instances, a dental implant which is made of metal only may come into contact with an abutment/crown which is also made of a metal like for instance titanium, titanium alloy, gold or a gold alloy. Alternatively the abutment/crown is made of ceramic such as zirconia-based, alumina-based (for instance in-ceram®) and/or sapphire-based ceramics, or a ceramic glass composite. In the first metal to metal case, saliva or tissue fluid, acting as an electrolyte, may cause a galvanic electric current to flow which in extreme cases may have unpleasant effects for the dental prosthesis bearer. Also the metal, in particular if metals other than titanium are used in contact with a titanium implant, may cause inflammation and irritation of the soft tissue which it contacts.
In view of the above, there is the need for a dental device, in particular a one-piece dental-device, that combines the advantages of metal made dental devices with those of ceramic made dental devices and which, at the same time, is not subject to the above shortcomings entailed by ceramic materials.
Furthermore, in view of the foregoing, there is the particular need for a dental implant, in particular a one-piece dental implant, that combines the advantages of metal made dental implants with those of ceramic made dental implants, which avoids the use of ceramic material.